CN100458347C

CN100458347C - Interconnected microchannel tube

Info

Publication number: CN100458347C
Application number: CNB200380101644XA
Authority: CN
Inventors: Y·沙布泰; 唐良猷
Original assignee: Outokumpu Oyj
Current assignee: Outokumpu Oyj
Priority date: 2002-11-26
Filing date: 2003-11-14
Publication date: 2009-02-04
Anticipated expiration: 2023-11-14
Also published as: WO2004048872A1; US20040099408A1; EP1565699A1; TW200415336A; CN1705858A; US20050241816A1; AU2003282133A1

Abstract

The invention relates to a microchannel tube for use in a heat transfer system. The microchannels have openings in the partitions that separate them from each other, thereby creating many short interconnected passages through which a heat transfer medium will flow. This permits the liquid and vapor phases of the medium to mix, thereby increasing the efficiency of the system.

Description

Interconnective micro-channel tubes

Technical field

The interconnective micro-channel tubes that the present invention relates to use in the heat transfer unit (HTU), the heat exchanger of described heat transfer unit (HTU) such as automobile or dwelling house or commercial air-conditioning.Micro-channel tubes is interconnective, is convenient to the efficient that steam-liquid mixes and improve heat exchanger mutually again.

Background technology

Micro-channel tubes was applied to air conditioning for automobiles unit and dwelling house or commercial heat exchanger of air condition in recent years.In use, cold-producing medium flows through a plurality of passages in the floating pipe (float tube).Cold-producing medium is evaporation and condensation when it flows through pipe, absorbs and release heat when it changes between liquid and gas.In the United States Patent (USP) 4998580 and 5372188 (" 188 patent ") each Patent publish have a condenser of little hydraulic diameter flow channel (being the microchannel).

The passage that the micro-channel tubes of current use has is isolated from each other, thus each passage when conducting heat and other channel separation work alone.This makes manages the imbalance of conducting heat between leading edge and pipe bias current (leeway) side, substitutes the mobile direction of unofficial biography thermal medium.The scope of 188 patents is restricted, because it needs hydraulic diameter in about 0.381 to 1.778 millimeter scope, wherein the hydraulic diameter cross-sectional area that is defined as each flow channel multiply by 4 and divided by the wetting girth of respective flow passage.

Therefore, need to improve the design of heat transfer of the heat exchanger that comprises micro-channel tubes, be used to improve heat transfer efficiency and make the whole width of pipe upload thermal balance more even.The invention provides these improvement.

Summary of the invention

The present invention relates to a kind of heat-transfer pipe, comprise overcoat around a plurality of next doors, the next door forms the microchannel in overcoat, heat transfer medium flows is by the microchannel, and the next door includes the sidewall in a plurality of holes, and heat transfer medium is flowed between the microchannel, thereby the liquid and gas of heat transfer medium are mixed, improving the heat transfer of pipe, and to keep main flow be laminar flow, its mesopore account for the next door sidewall area 1% to 20%.

5 holes are had an appointment to every 75mm 1 hole of having an appointment along the every 25mm of next door length direction in each next door.These holes account for separates the maximum about 80% of sidewall height, and can be circular, oval, square, rectangle or triangle.

In one embodiment, have 2 to 12 next doors at least, thereby have at least 3 to 13 microchannels in the pipe.Preferably, have 4 to 8 next doors at least, thereby have at least 5 to 9 microchannels in the pipe.The next door is preferably formed by single thin slice, is preferably formed as a kind of of serpentine partitions.

Overcoat and next door are to be made of metal, aluminum or aluminum alloy for example, but copper or copper alloy are preferred.If desired, load onto fin, help therefrom to conduct heat at the outer surface of overcoat.

The invention provides a kind of heat exchanger, comprise two relative heads and a plurality of heat-transfer pipe that between head, extends, heat-transfer pipe comprises the overcoat around a plurality of next doors, and the next door forms the microchannel in overcoat, and heat transfer medium flows is passed through the microchannel, the next door includes the sidewall in a plurality of holes, heat transfer medium is flowed between the microchannel, thereby the liquid and gas of heat transfer medium are mixed, to improve the heat transfer of pipe, and to keep main flow be laminar flow, its mesopore account for the next door sidewall area 1% to 20%.

An alternative embodiment of the invention relates to heat exchanger, described heat exchanger comprises a plurality of microchannels, heat transfer medium flows through the microchannel, a plurality of holes are provided in the microchannel, thereby heat transfer medium flows between the microchannel, the liquid and gas of heat transfer medium is mixed, so that improve the heat transfer of pipe, and to keep main flow be laminar flow, its mesopore account for the next door sidewall area 1% to 20%.

Description of drawings

Accompanying drawing referring to the explanation preferred embodiment will be understood the present invention better.In the accompanying drawings:

Fig. 1 is the cutaway view of heat exchanger tube of the present invention;

Fig. 2 is the perspective view of heat exchanger tube of the present invention;

Fig. 3 is the cutaway view of heat exchanger along 3-3 line among Fig. 1.

The specific embodiment

Referring to accompanying drawing, express heat exchanger tube according to the present invention among the figure and form by overcoat 10 and microchannel 12.Heat-transfer pipe is formed by a plurality of next doors 14 that form a plurality of microchannels 12.Heat transfer medium flows through microchannel 12.In one embodiment, the present invention includes at least 2 to 12 next doors, form at least 3 to 13 microchannels.Have at least 4 to 8 next doors in another embodiment, in overcoat, form at least 5 to 9 microchannels.

Microchannel 12 forms the passage of heat transfer medium flows.When heat transfer medium flows through the microchannel, its evaporation or condensation, thereby gas phase or liquid content in the change composition.The microchannel of pipe leading edge and pipe bias current (leeway) edge are because external cause can have the heat transfer of varying level.Therefore, be positioned near the microchannel of pipe leading edge than being positioned at the gas phase (or liquid phase) that near microchannel, bias current edge has much more quantity.Therefore need the design microchannel, making these pass the microchannel on the whole width of pipe is uniformly, conducts heat so that optimize two-phase flow.Find now the aperture between the passage or the hole helps and can make gas phase and liquid phase is evenly to mix and distribute on all microchannels of pipe, conduct heat thereby strengthen.

Opening in the next door 14 or hole 20 can be Any shape, for example slit, rectangle, square or triangle, but preferred shape is a circle or oval, because these shapes do not produce the sharp edges of stress in structure.Hole 20 allows liquid to mix with steam and produces mutually variation simultaneously, thus the flowing of balanced liquid and steam.This mixing makes the efficient high about 20% to 50% of single heat-transfer pipe than the contrast pipe that does not have hole 20 in the next door 14.Has the efficient high about 10% to 30% of the heat exchanger of a plurality of this pipes than conventional heat exchanger.

It is important that the gas phase of heat transfer medium and liquid phase are mixed this efficient, can not be too strong but mix.Generally need to flow to remain under the laminar flow condition, decline will be too big because turbulent flow will cause pressure, can influence the efficient of system.

The hole can be various sizes, but generally is no more than 80% of next door height.The width in hole generally is not more than its height.Because the exemplary height in next door is about 2mm, then maximum size hole will be the square of about 1.6mm * 1.6mm.The circular hole of the about 1.5mm of diameter is available, and oval-shaped is 1.5mm than major diameter, than minor diameter be 1mm or or even 0.5mm, stride across the next door height than major diameter.Have an appointment 5 holes to every 75mm length 1 hole of having an appointment along the normally every 25mm length of the length direction of pipe, and preferably every 25mm length has 2 holes to every 50mm length 1 hole to be arranged.The layout neither one critical condition in hole, they can be arranged by uniform mode or mode staggered or skew.The hole is formed by the cutting next door simply, and removes about 1% to 20% of each next door area.In a preferred embodiment, about 5% to 10% of next door area is removed in the hole.Area between the hole must be enough big, do not destroy the mechanical strength of pipe, and can bear the pressure of the heat transfer medium that wherein flows.

Pipe and next door can be made by metallic plate.Though can make pipe and next door with aluminium sheet, preferably form pipe and next door with copper or copper alloy plate.The latter has superiority, because it does not need the coating of soldering, and aluminium needs.Heat exchanger tube can be made by two, outside overcoat and inner next door, and it can be a corrugated fin.Pipe also can utilize folding technology to make by the single piece of metal plate.In inner partition, cut the hole simply, form the flow channel between the microchannel.

But overcoat 10 and next door can be made by any suitable brazing material, and this is persons skilled in the art material known, as metal, alloy or or even composite.As mentioned above, preferable material comprises copper and copper alloy or aluminium and aluminium alloy.The exemplary alloy element of copper alloy comprises zinc, tin or nickel.In one embodiment, pipe is the light-wall pipe that the brass that is welded into is made.For convenience, the next door can be with making with the overcoat identical materials.

The suitable soldering packing material of general employing is connected in next door 14 on the overcoat 10 by soldering.For the overcoat that copper or copper alloy are made, soldering processes can be included in next door 14 and apply next door 14 with solder paste before inserting overcoats 10, perhaps the brazing foil of next door 14 with 14 both sides, next door inserted in the overcoat 10, thereby next door 14 is connected on the overcoat 10.Partition insert can be covered solder paste with roller coat.Preferred brazing alloy is copper-nickel-tin-phosphorus alloy, OKC600 for example, and it can have been bought in market.OKC600 comprises about 1% to 5% nickel, about 15% to 20% tin, and about 4% to 7% phosphorus, and all the other are copper.Do not need this brazing material is added solder flux, because phosphorus as solder flux, makes copper-nickel-Xi-phosphorus become self-fluxing alloy.Joint that obtains and structure also have etch resistant properties preferably, because there is not solder flux.And, owing to there is not remaining solder flux to need to remove, therefore be convenient to cleaning.

For the structure of aluminum or aluminum alloy, overcoat 10 inside have coating, and next door 14 coating not.In addition, coating can be applied to next door 14, rather than is applied in overcoat 10 inside.This coating has improved brazing operation.

If desired, can walk between overcoat 10 at the outer surface connection fin and the fin of overcoat 10, being convenient to derives heat from overcoat 10, and extra surface area is provided, and flows through heat exchanger by air and realizes convection heat transfer' heat-transfer by convection.Overcoat can apply brazing material by rolling or spraying, and is convenient to the combination of fin.OKC600 is copper or the preferred brazing material of copper alloy overcoat.For the overcoat 10 that aluminum or aluminum alloy is made, the outside of overcoat 10 or fin will obtain coating, make fin be attached to outer putting.Coating fusing in brazing process and under flux helps forms soldered fitting.

A plurality of pipes can be connected to form heat exchanger.Heat exchanger is included in each terminal head of a plurality of pipes.Head can be with making with pipe and next door insert identical materials.In one embodiment, head is made by copper or copper alloy and is slotted, and is used for collecting pipe.In assembling process, fin is inserted between the pipe.Head is coated with solder paste, wears the cap that is coated with cream, and inserts pipe if desired, and solder paste is coated on the joint.

Middle porose MCA passes cold-producing medium between passage, improve heat and distribute and performance.The flow channel that this has increased heat transfer medium basically makes it be more prone to circulation.In fact the microchannel forms the interconnective passage of a lot of weak points, and heat transfer medium can flow through by these passages.By this way, the medium of liquid and gas mixes on the width of pipe more equably, thereby strengthens the heat transfer of heat exchanger, and increases the energy efficiency of system.

Brazing process generally carries out in stove.The problem of a care is to prevent to manage or the oxidation of brazing material in this process.The dew point of stove is lower than-40 ℃ approximately, and oxygen content is lower than about 100ppm.Usually use inert atmosphere, for example dew point is lower than approximately the nitrogen that-65 ℃ and oxygen content are lower than about 10ppm.

It should be understood that the present invention is not limited to the accurate structure that illustrates and describe here.Therefore, one of ordinary skill in the art obtains all interim modifications from content given here or the test by routine easily, and these modifications will be in the spirit and scope of the invention that claim limits.

Claims

1. heat-transfer pipe, comprise overcoat around a plurality of next doors, the next door forms the microchannel in overcoat, heat transfer medium flows is by the microchannel, and the next door includes the sidewall in a plurality of holes, and heat transfer medium is flowed between the microchannel, thereby the liquid and gas of heat transfer medium are mixed, improving the heat transfer of pipe, and to keep main flow be laminar flow, its mesopore account for the next door sidewall area 1% to 20%.

2. heat-transfer pipe as claimed in claim 1 is characterized in that existing at least 2 to 12 next doors, thereby forms at least 3 to 13 microchannels in pipe.

3. heat-transfer pipe as claimed in claim 1 is characterized in that existing at least 4 to 8 next doors, thereby forms at least 5 to 9 microchannels in pipe.

4. heat-transfer pipe as claimed in claim 1 is characterized in that each next door is per 25.4 millimeters along the hole number of next door length direction and has 5 holes to per 76.2 millimeters 1 hole to be arranged.

5. heat-transfer pipe as claimed in claim 1, it is characterized in that the hole account for the next door the sidewall height at the most 80%.

6. heat-transfer pipe as claimed in claim 1 is characterized in that the hole is circle, square, rectangle or triangle.

7. heat-transfer pipe as claimed in claim 1, what it is characterized in that a plurality of next doors is to be made by an independent plate.

8. heat-transfer pipe as claimed in claim 7 is characterized in that plate forms serpentine partitions.

9. heat-transfer pipe as claimed in claim 1 is characterized in that overcoat made by copper or copper alloy.

10. heat-transfer pipe as claimed in claim 9 is characterized in that the sidewall in next door is made by copper or copper alloy.

11. heat-transfer pipe as claimed in claim 1 is characterized in that the sidewall in overcoat and next door is made by aluminum or aluminum alloy.

12. heat-transfer pipe as claimed in claim 1 also comprises the fin on the outer surface that is connected overcoat, thereby helps to conduct heat.

13. heat exchanger, comprise two relative heads and a plurality of heat-transfer pipe that between head, extends, heat-transfer pipe comprises the overcoat around a plurality of next doors, and the next door forms the microchannel in overcoat, and heat transfer medium flows is passed through the microchannel, the next door includes the sidewall in a plurality of holes, heat transfer medium is flowed between the microchannel, thereby the liquid and gas of heat transfer medium are mixed, to improve the heat transfer of pipe, and to keep main flow be laminar flow, its mesopore account for the next door sidewall area 1% to 20%.

14. heat exchanger, comprise a plurality of microchannels, heat transfer medium flows through the microchannel, in the microchannel, form a plurality of holes, thereby heat transfer medium flows between the microchannel, the liquid and gas of heat transfer medium is mixed, to improve the heat transfer of pipe, and to keep main flow be laminar flow, its mesopore account for the next door sidewall area 1% to 20%.